Apparatuses and methods of shaping plastics material pre-forms into plastics material containers have long been known from the prior art. An apparatus of this type for the shaping of plastics material pre-forms into plastics material containers, also referred to below as a stretch blow moulding machine, usually has a plurality of blow moulding stations in which the pre-forms are blow moulded into plastic bottles by the application of an internal pressure. These finished blow moulded plastics material containers are soiled after this process and have to be cleaned in a complicated manner afterwards in order to observe hygiene standards.
An important component of such a stretch blow moulding machine or of such a stretch blow moulding station respectively is the stretching unit. This supports and guides the stretch bar. The stretch bar moves into the plastics material pre-form and stretches it out as far as the base of the mould. The blow moulding pressure eventually shapes the bottle and the stretching unit moves back out of the finished bottle again.
It is known from the prior art for the stretching unit to be connected and guided on a linear guide by way of a moment slide or stretch slide. This is important since the stretch bar usually has to be guided centrally in a very precise manner over a very long stroke which amounts to up to 450 mm. The stretch slide in this case is driven in its known design by a linear motor. The latter is mounted centrally with respect to the stretching axis and moves in and out at very high speed.
It is also known for the stretch bars to be moved by way of a guide cam.
In the prior art the mechanism in a non-clean room is without any protection from contamination. This means that the ready shaped bottle is contaminated and so has to be cleaned hygienically in a separate module, such as a rinser.
A sterile blow moulding machine is known from WO 2010/020529 A2. The subject matter of this publication is hereby also made the subject of the present application by reference in its entirety.
At present no stretch blow moulding machines are known which produce plastic bottles which are blown aseptically. The mechanism and the “non-clean course” of the stretching process are similar in all the current machines on the market.
Therefore, it may be desirable to provide a stretch blow moulding machine which, in particular, also has a hygienically designed stretching unit.